The HPTA axis stands for hypothalamus, pituitary, testes axis and this is the main mechanism for producing testosterone. The testosterone in turn aromatizes into a certain amount of estrogen that we have learnt is very important for controlling bad cholesterol. The hypothalamus is the first action that must take place in the regulation of testosterone and estrogen. The function of the hypothalamus is to sense low estrogen and it senses if the androgen levels are not as high as what it should be. When it senses an imbalance it produces LHRH (LH releasing hormone) that signals the pituitary to produce LH (luteinizing hormone). The last step is for the LH to stimulate the testes to produce more testosterone. On the flip side if it senses too much testosterone the mechanism shuts.
When you take Anabolic steroids the hypothalamus will sense an excessive amount of testosterone and the HPTA shuts down. It does not produce any natural testosterone because you are constantly in overload. When the HPTA axis shuts down for a long time HCG will help with testicular atrophy (testicle shrinkage) but it does not resolve the rest of the process that includes the hypothalamus and pituitary gland. The responsiveness of these two glands is very poor after extended steroid use and they need to be activated. This action is called a “feedback loop of the HPTA” that senses low estrogen and androgen levels. The glands must become responsive again and needs a bit of a kick-start.
Clomid and Nolvadex both work by binding to the sites of the estrogen receptor cells without activating these receptors. Estradiol cannot bind to these receptor sites to activate them and therefore the hypothalamus does not pick up any signals of estrogen and has to activate LHRH accepting that the estrogen levels are low and this stimulates the pituitary gland. The entire mechanism gets activated hereby and the pituitary gland releases LH and the testes manufacture testosterone. Using HCG with Clomid now makes perfect sense because it activates the HPTA from both ends.
Nolvadex and Clomid are both estrogen agonist and antagonists depending on certain tissues in the body. Both Clomid and Nolvadex are anti estrogenic (antagonist) in breast tissue as well as the hypothalamus gland and stop the negative feedback. Both these agents are good for anti-gyno as well. Clomid differs however by being an estrogen agonist in the pituitary. This enhances its value as a PCT over Nolvadex. Because Clomid has estrogenic (agonist) effects in some neurons in the brain Clomid causes a person to be much more emotional. Nolvadex on the other hand has been seen to cause a decrease in libido where Clomid does not have this characteristic. Clomid and Nolvadex should never be used together and the athlete should choose its preference in agent.
Clomid is a 50mg tablet. On the first day as a PCT you must take 300mg (2 tablets every 8 hours on the first day). This dose will immediately get levels to where it needs to be. After day one dose of 50mg per day will maintain the levels. The PCT should be done as soon as the androgen levels from the anabolics worked out and levels are down to normal. In other words after short esters you can start quicker than after taking long acting esters. PCT must be taken until testosterone production has been restored completely.
Side effects of Clomid are increased emotionalism and vision disturbance. If your vision becomes impaired you should stop the use of Clomid immediately and rather use Nolvadex as an alternative.